You are wrong again. Working backwards to finding the result is exactly what didn't happen, just the opposite. For the LDS, Friday Apr 1, 33 AD has been the known date for the Crucifixion since 1830 when Joseph revealed that Christ had been born 1830 years earlier from April 6, 1830, when The Church of Jesus Christ of Latter Day Saints was officially organized. Several LDS prophets between then and now have confirmed that April 6, 1 BC is the birth date of Christ. Since the Bible implies He lived 33 yrs, and was crucified on Friday Nisan 14, it must have been on Fri Apr 1, 33 AD if you believe He was born on Passover, 1 BC. So that date has been long known by the LDS, and even many non LDS scholars have pinpointed that date as one of the most likely for the Crucifixion date as the day before the Passover feast falls on a Friday only three times in the decade of possibilities. The other beginning date for Daniel's prophecy, Apr 3, 458 BC comes from secular sources. John Pratt emphasized the following point, which seems, as usual, a crucial point that you have missed: "Ezra provides us with the exact date of when he left to begin to restore Jerusalem. He states that it was on the first day of the first month of the seventh year of Artaxerxes that he left Babylon to restore Jerusalem (Ezra 7:7-9). Sir Isaac Newton placed that event in the year 458 BC, but saw no need to refine that estimate further. What does modern scholarship say about that date?
The standard reference for dates of that period on the Babylonian calendar is a set of tables produced by Parker and Dubberstein, which give the exact day for the first day of every month. The day listed in their tables, which is guaranteed not to have been influenced by any desire to force the prophecy to come out neatly, is Sat 3 Apr 458 BC."
So the beginning 3 Apr 458 BC and end 1 Apr, 33 AD dates are independent of each other and not chosen to fit. Both dates are Passover and exactly 490 years to the day apart from each other on the Enoch Calendar. Which is an absolute bullseye for Daniel's prophecy. Given the prophecy is given in weeks of years, and the Enoch calendar is based on weeks (of days), it is a perfect fit.